[M2M]

Hi, I've seen photos of this particular GAZ engine before; a guy on Facebook contacted me a few months ago. The engine number puts it well into the 1960s, but this block actually has a casting date of Dec 1966...take a good look at the block and you'll find it. The number on the head is also likely to be a casting date of Dec 1965 which you can see in the photo above. The last digit in a Russian casting date is often (but not always) the batch number so you need to remove it to understand the date. In the late 1950s B block production was moved from the GAZ plant to the ZMZ plant (Zavolzhsky Motorny Zavod).

http://www.zmz.ru/eng/about/factory

These B blocks were made in small numbers until the early 1970s.